Maternal experiences are a series of events such as pregnancy, delivery, lactation and rearing. We questioned if those events can change the behavior and the neural system of the mother rats. Behavioral changes during postpartum period are well documented in rats. The main factor is considered to be a drastic reduction of estrogen levels after delivery. In addition, we demonstrated that changes in sensitivity to estrogen after delivery by comparing experimental groups of primiparity rats and nulliparity controls at the same age. In this study consisting of the similar groups, five-weeks postpartum rats that resumed estrus cycle after weaning were subjected to Morris water maze and Y-maze tests for spacial learning assessments. In electrophysiological study, we used a standard protocol for inducing long-term potentiation using whole-cell recording to pair low-frequency synaptic stimulation (270 pulses, 3 Hz) with a depolarizing voltage-clamp pulse (1.5 min duration). Furthermore, the expression level of GluR 1 and 2 was analyzed in the hippocampus by western blot using synaptic fraction. Improved performance of primiparous rats was found in Y maze and Morris water maze. The expression of GluR 2 level was increased in the hippocampus of primiparous rats. Taken together, reproductive experience could change hippocampal function leading to improve spatial learning.